Pilot-scale evaluation of micropollutant abatements by conventional ozonation, UV/O_3, and an electro-peroxone process

摘要

The electro-peroxone (E-peroxone) process is an emerging ozone-based advanced oxidation process (AOP) that has shown large potential for micropollutant abatement in water treatment. To evaluate its performance under more realistic conditions of water treatment, a continuous-flow pilot E-peroxone system was developed and compared with conventional ozonation and a UV/O-3 process for micropollutant abatements in various water matrices (groundwater, surface water, and secondary wastewater effluent) in this study. With a specific ozone dose of 1.5 mg o(3)/mg DOC, micropollutants that have high and moderate reactivity with ozone (O-3) (diclofenac, naproxen, gemfibrozil, and bezafibrate) could be sufficiently abated (90% abatement) in the various waters by all three processes. However, ozoneresistant micropollutants (ibuprofen, clofibric acid, and chloramphenicol) were abated only by similar to 32 -68%, 68-91%, and 73-90% during conventional ozonation of the selected groundwater, surface water, and secondary wastewater effluent, respectively. By electro-generating H2O2 or applying UV irradiation to enhance o(3) transformation to center dot OH during ozonation, the E-peroxone and UV/O-3 processes similarly enhanced the abatement efficiencies of ozone-resistant micropollutants by similar to 15-43%, similar to 5-15%, and similar to 5 -10% in the groundwater, surface water, and secondary wastewater effluent, respectively. In addition, the E-peroxone and UV/O-3 processes significantly reduced bromate formation during the treatment of the three waters compared to conventional ozonation. Due to its higher efficiency, the E-peroxone process reduced similar to 10-53% of the energy consumption required to abate the concentration of chloramphenicol (the most ozone-resistant micropollutant spiked in the waters) by 1 order of magnitude in the three waters compared to conventional ozonation. In contrast, the UV/O-3 process consumed approximately 4 -10 times higher energy than conventional ozonation. This pilot-scale study demonstrates that the E-peroxone process can provide a feasible, effective, and energy-efficient alternative for micropollutant abatement and bromate control in water and wastewater treatment. (C) 2018 Elsevier Ltd. All rights reserved.